We did test compatibility with Windows 10 and seems to be working fine on our side. The fact problem is across all browsers might indicate it is something to a common component. Nonetheless, it could be something related to a specific setup. Can you kindly provide us with:
1. Windows 10 build and version being used please.
2. Details on the Add-ons you referred to as "all browser video add-ons have been updated to newest version"
3. The courses which did not work